Collegium Musicum 90 is one of Britain's best-known and highly regarded period-instrument ensembles. One of its unusual features is that it was founded and directed by two leaders, one most associated with historical music performance and the other with his work with standard modern orchestras. Born in 1941, violinist Simon Standage is one of the best-known instrumentalists on London's busy period instruments stage. He has played in modern music ensembles, having been a sub-leader (i.e., assistant concertmaster) of the English Chamber Orchestra (1974-1978) and leader (concertmaster) of the City of London Sinfonia (1980-1989). However, he became best known as the leader of the English Concert (1973-1991), the famous period-instrument group founded by harpsichordist Trevor Pinnock, and as the first violinist of the Salomon Quartet, the first major British quartet to use period string instruments -- instruments set up with the same sorts of strings, bows, bridges, and so forth as in the period of the music to be played. Richard Hickox, six-and-a-half years younger, was an organ scholar at Queen's College Cambridge who in 1971 founded the City of London Sinfonia and the Richard Hickox Singers and specialized in Baroque music, but on regular instruments. Despite his initial reputation for Baroque music, his skills as a choral conductor in particular eclipsed it, and in 1976 he became the conductor of the London Symphony Chorus. He also has had leadership positions with the Netherlands Radio Philharmonic, the Northern Sinfonia, the San Diego Symphony Orchestra, and the London Symphony Orchestra. It was in the midst of this success (which also included Hickox's frequent conducting of opera) that Standage and Hickox in 1990 co-founded the Collegium Musicum 90 to be a standing Baroque period orchestra. (The name Collegium Musicum, or musical guild, has been used in the names of so many groups that it is practically a generic term for Baroque-era ensembles.) It has become Hickox's primary means of performing the Baroque music that interested him so much in the early part of his career. Collegium Musicum 90 established itself quickly. It gained an exclusive contract with the British record company Chandos and has made several records. It has toured Europe and most of the major British music festivals. It has performed at the BBC Promenade Concerts, the City of London Festival, and the Cheltenham Festival, and its recording of Purcell's Dido and Aeneas was chosen by the BBC to be the soundtrack of a filmed version of the opera made in connection with the Purcell tercentenary observances in 1995.